Engine



FIG. 1 is a top view of an engine according to an embodiment of our design;

FIG. 2 is a bottom view thereof;

FIG. 3 is a front view thereof;

FIG. 4 is a rear view thereof;

FIG. 5 is a right side view thereof; and,

FIG. 6 is a left side view thereof.

The broken lines shown in FIGS. 1-6 disclose unclaimed subject matter, are for environmental purposes only, and thus form no part of the claimed design. 

The ornamental design for an engine, as shown and described. 